This invention relates to an enzyme electrode for measuring urea dissolved in a solution and to a process for preparing the same, and particularly to an enzyme electrode suitable for quantitative determination of urea in a short time and a process for preparing the same.
Enzyme electrode immobilized with an enzyme having a high reaction specificity to a substrate (test sample) and combined with an ion electrode, etc. were developed about ten years ago [G. G. Guilbault: Handbook of Enzymatic Method of Analysis, Marcel Dekker, New York (1976)], and some of such electrodes have been recently practically utilized, one of which is a urea electrode directed to urea as a test sample. Several types are available for the urea electrode, one of which uses urease as an enzyme and has such a structure that a urease-immobilized enzyme membrane is provided near an ammonium ion-selective electrode. However, a urea electrode of such type requires a long time in measuring one sample. This has been a problem.